ES2914679T3 - Structural block assembly having a tensioning system - Google Patents

Abstract

A structural block assembly having a tensioning system to contribute to the tensile load bearing attributes of the structural assembly, the structural assembly comprising: a plurality of structural blocks, each structural block having a first surface, an opposite surface, side surfaces opposite and opposite end surfaces; a plurality of load-bearing structural members embedded within each structural block, these being strut members, a protruding end of each embedded member extending from said first surface of the structural block, wherein one or more of the embedded strut members comprise a longitudinal cavity through them; a plurality of openings extending into the structural block from said opposite surface of the structural block, each opening adapted to engage a protruding end of an embeddable member of an adjacent structural block, the protruding end of each embeddable member extending from the first surface a distance equal to the depth of the opening within the block such that the protruding end of an embed member of one block engages an opening in an adjacent block and is in direct contact with the terminal embed end of an embed member of the block. adjacent block; and wherein the embedded members of the assembled structural blocks form a stacked structure that forms a load-bearing structural member, wherein the assembly further comprises tensioning means placed within the longitudinal cavities of the embedded members, wherein the cavities of the embedded members of adjacent structural blocks are aligned to form a longitudinal duct for receiving the tensioning means therein; wherein the openings and protruding ends of the embedded members function as locating means to accurately position a structural block relative to an adjacent block during assembly while also contributing to the load-bearing attributes of the block under compression; characterized in that each structural block further comprises a compression strut extending in an approximately perpendicular direction between and in contact with a pair of embedded members of the structural block.

Description

DESCRIPTION

Structural block assembly having a tensioning system

field of invention

The invention disclosed herein relates to particular construction materials, as well as processes for the preparation and uses of such materials. Said materials may be intended to be used as structural elements, such as structural blocks, used in the construction of buildings and civil engineering structures.

Background of the invention

The production of masonry blocks using vegetable additions incorporated in a lime-based binder matrix (eg, hemp used to produce Chanvribloc™ blocks) is a process known in the art.

The prior art also discloses blocks used in the construction of structures, such as houses and commercial buildings, which may have properties that are insulating or load-bearing.

Document WO 2014072533 discloses an insulating construction material with a supposedly low thermal conductivity comprising vegetable additions, as well as a process for the preparation and uses of said material. A building block assembly according to the preamble of claim 1 is known from KR 100899779 B1.

It would be advantageous if there were a structural block that had a composition and configuration that integrate both load-bearing capacities with insulating properties.

It would also be advantageous if there were additional means to provide additional reinforcement and stress-bearing capabilities to a structural block.

Summary of the invention

The invention described herein relates to particular construction materials, as well as processes for the preparation and uses of such materials. Said materials may be intended to be used as structural elements, such as structural blocks, used in the construction of buildings and civil engineering structures. When the materials are used in the production of structural blocks, these blocks can integrate load bearing capacities together with insulating properties. In one embodiment, the block of the present invention may be further adapted to accommodate a tensioning system that may provide tension. As such, the block of the present invention can be adapted to withstand stress as well.

According to the present invention, there is provided a building block assembly according to claim 1 and the use of said building block assembly.

Optional preferred features are set out in the attached dependent claims.

The specification also discloses, but is not specifically claimed, a method of fabricating a structural block tensioning system to contribute to the tension-bearing attributes of a structure, comprising assembling a plurality of interlocking structural blocks, in wherein each block comprises a plurality of embedded members and a plurality of openings, one end of each member extending from one surface of the block, and openings extending into the block from an opposite surface of the block, the openings adapted to engage a extending end of an adjacent structural block, forming a longitudinal cavity in one or more of the embedded members, joining the plurality of interlocking structural blocks by inserting the extended ends of the embedded members of one structural block into openings in an adjacent block , wherein the cavities of one or more embedded block members Adjacent s are aligned to form a conduit, pass a tensioning means through the longitudinal cavities of the one or more embedded members of adjoining structural blocks, and tighten the tensioning means.

Other aspects, features, and advantages of the present invention will become apparent from the following descriptions and claims.

Brief description of the drawings

The subject matter which is considered as the invention is particularly pointed out and clearly claimed in the final part of the specification. The invention, however, may be better understood by reference to the following detailed description of various embodiments and accompanying drawings in which:

Figure 1 is a front perspective view of a structural block according to the present invention;

Figure 2 is a bottom perspective view of the structural block of Figure 1;

Figure 3 is a bottom view of the building block of Figures 1-2;

Figure 4 is a top view of a structural block according to the present invention;

Figure 5 is a front perspective view of a structural block comprising ducts therethrough, according to a preferred embodiment of the present invention;

Figure 6 is a bottom perspective view of the structural block of Figure 5;

Figure 7 is a bottom view of the building block of Figures 5-6;

Figure 8 is a top view of a structural block comprising perforated struts according to a preferred embodiment of the present invention;

Figure 9 is a front view of the structural block of Figure 8;

Figure 10 is a side view of the building block of Figures 8-9;

Figure 11 is a perspective view of a structural block adapted to accommodate a tensioning system therethrough in accordance with the present invention;

Figure 12 shows various views and types of structural blocks adapted to accommodate a tensioning system in accordance with the present invention;

Figure 13 is a perspective view of a preferred embodiment of a tensioning system comprising a hexagonal stamping tensioner according to the present invention;

Figure 14 shows various views and types of structural blocks adjoining each other through a tensioning system according to the present invention;

Figure 15 is a top view of a structural block adapted to accommodate a compression strut in accordance with the present invention;

Figure 16 is a front view of the structural block of Figure 15;

Figure 17 is a side view of the building block of Figures 15-16;

Figure 18 is a front view of another structural block adapted to accommodate a compression strut in accordance with the present invention;

Figure 19 is a side view of the structural block of Figure 18;

Figure 20 is a rear view of the structural block of Figures 18-19; Y

Figures 21-33 show different views of a building construction according to the present invention using the blocks of the present invention.

Description of the preferred embodiment

The present invention relates to particular construction materials, as well as processes for the preparation and uses of said materials. In describing the present invention, any term or expression not expressly defined herein will have its commonly accepted definition understood by those skilled in the art.

The building materials of the present invention are intended to be used in structural elements for building structures and civil engineering structures.

In one embodiment, the materials are used in the production of building blocks. In one aspect, the blocks of the present invention can be designed to integrate compressive and torsional load-carrying capabilities with insulation properties,

Figures 1-4 illustrate building blocks according to preferred embodiments of the present invention. As illustrated in Figures 1-4, each block of the present invention may comprise a body shape configured to allow it to interlock with other blocks when building a structure, such as a wall or a house. Such a design can provide additional strength to the overall structure.

Each block accommodates a plurality of embedded members. Each member, which is a strut, is embedded within the block and contributes to the load bearing properties of the block, particularly compressive loads. One end of the embedded member protrudes a given distance from one side of the block, while the opposite end of the embedded member terminates partially within the block on an opposite side.

A recess or hole (referred to as an opening in the claims) is formed within the block and extends from the terminal end of the member embedded within the block to the surface of one side of the block, opposite the side through which the member protrudes. embedded.

The extended end of the embedded member protrudes from the block a distance that is roughly equivalent to the depth of the recess within the block. As an example, a block with a height of 20.32 cm (8 inches) can accommodate an embedded member 20.32 cm (8 inches) long, one inch corresponds to 2.54 cm. The protruding end of the member may extend 5.08 cm (2 inches) from the surface of one side of the block, with the remaining 15.24 cm (6 inches) embedded within the block. A recess formed within the block at the opposite end of the member may be 5.08 cm (2 inches) deep. The recess may extend immediately from the terminal end of the embedded member housed in the block, to the surface of the opposite side of the block.

A recess can be sized, shaped, and spaced from others to align with and accommodate the protruding end of an embedded member from another block. Such an arrangement is similar to a "pin and socket" interlocking arrangement and functions as a locating means in order to accurately position one block relative to additional block(s) while also contributing to the load bearing attributes of the block under compression.

When the projecting end of an embedded member of one block is placed in the corresponding recess of a second block, the projecting end of the embedded member is in direct contact with the terminal end of the embedded member of the second block. As a result, the blocks automatically align and the embedded members form a stacked structure that forms a load-bearing structural member.

To facilitate assembly, a recess within the block may have a width that is one measurement greater than the width of the embedded member. In one embodiment, the width of the recess may be 1/4 inch (0.635 cm) wider than the width of the member, for example, 1/8 inch (0.3175 cm) on each side of the recess (on each on all four sides when the block and recess are square), to accommodate ease of inserting the projecting member from an adjacent block.

Any suitable binding agent, such as lime mortar, can be used to bond the projecting end of an embedded member of one block into the corresponding recess of a second block. Such a bond, when formed, can be stronger than the block itself.

When the embedded member and the corresponding recess are interlocked, a molecular bond can be formed which can contribute to the load-bearing or other structural properties of the block. In some cases, the load-bearing capacities of the block of the present invention can be several times greater than that of a hollow concrete block, and more similar to or greater than that of a conventional stud-framed wall structure.

In another embodiment, holes can be created in the block that can be placed at the same distance between the embedded members. As illustrated in Figures 5-7, the holes can be used to create a conduit to accommodate electrical wiring or other utilities inside, for example, the wall of a structure. The holes can also be beneficial to the curing process, by exposing the interior of the block to, for example, injected carbon dioxide. In an alternative embodiment, some strut members may be hollow and slotted. As illustrated in Figures 8-10, in another embodiment, additional perforated tubes or struts may be incorporated into the blocks passing through them.

The composition of the strut itself may comprise any rigid material or mixtures thereof, with any preference to the materials used directed to considerations of cost and load carrying capabilities of the material. In a preferred embodiment, the embedded member may comprise any wood material, such as fir, spruce, pine, cedar, etc. The element may also comprise organic or inorganic fiber compounds, such as hemp or carbon fiber, etc. In another embodiment, the embedded member may comprise a blend of biofibers and polymers, such as polyethylene, polypropylene, or polyester. Some compatible metals can also be used. According to the invention, the strut is hollow, like a hollow square or cylindrical tube. Other materials may include metals, carbon fiber or composites, 3D printed or extruded plastics, or any suitable structural member.

tensioning system

The block of the present invention can be adapted to also withstand tension. As illustrated in Figures 11-12, a block is further adapted to accommodate a tensioning system that provides tension. According to the invention, the embedded member of the block accommodates tensioning means along the member, said tensioning means entering at one end of the member and exiting at the other end of the member.

In one embodiment, the tensioning means may be a cable, such as a non-stretchable stainless steel tension cable. In an alternative embodiment, the system may comprise a rod.

As illustrated in Figure 13, when the tensioning system includes a cable, the tensioning end assembly may comprise a hex swage tensioner in addition to the cable.

As illustrated in Figure 14, when assembled, the embedded members of each block align with the corresponding members of other blocks, to allow the passage of the tensioning means through multiple elements and embedded blocks.

Such a configuration provides additional fastening means for a structure comprising the blocks of the present invention. In particular, such a configuration is tension-bearing, in the sense that the blocks are joined together through adequate tension for non-vertical structural elements such as floors, walls, sloped or flat roof surfaces, etc.

According to the invention, an additional member, which is called a compression strut, is used in order to increase the compressive strength of the structural element formed by stressed blocks. As illustrated in Figures 15-20, a compression strut is placed approximately perpendicular between and in contact with a pair of existing struts, integrated into the body of the block, each of which accommodates a cable as tension means. . The compression strut application helps keep the pair of embedded members properly spaced, without the need for structure inherent in the block material, by keeping adjacent pairs of tensioned struts and cable or rod essentially equidistant along their entire length.

In accordance with the present invention, other elements such as strut caps and/or mounting plates may be used. By way of example, a strut cap may be placed in a block over the projecting end of an embedded member, with the extending end protruding from the cap.

In practice, the tensioning means may be tensioned after construction, after the blocks have been aligned.

When the tensioning means comprises a cable, the tensioning procedure with respect to a ceiling, for example, may include the following steps:

(i) The beams can be assembled using the tension blocks on a flat horizontal surface and prestressed by the use of cables and lifted into position. Alternatively, scaffolding would be required to assemble in place and post-tension the blocks using cables.

(ii) Once the roof is built (minus the end caps), the non-swaged end of the cable is fed through the embedded member, starting at the top of the roof.

(iii) The cable is pulled to tighten it.

(iv) The second end of the cable is stamped as close as possible to the hex turnbuckle.

(v) The hex turnbuckle is tightened as necessary.

In one embodiment, the frequency of the tensioning means may have to be applied only as required, for example every meter of the assembled structure, to form a floor, ceiling or other non-vertical structure, or it may be a wall. Biofiber building block

In a preferred embodiment, the block body of the present invention may comprise a primarily fibrous and lime composition. Specifically, the composition of each block may comprise the following components:

(i) hemp tow, and fibers

(ii) flax fiber

(iii) hydraulic lime

(iv) hydrated lime

Certain benefits may be obtained by practicing a block comprising the preferred composition of the present invention. Compositions comprising hemp tow, flax, hydraulic lime and hydrated lime can be environmentally sustainable, recyclable and can capture carbon dioxide from the atmosphere, while providing exceptional insulating qualities.

While a concrete block may be restricted in size, for example, 16 inches (40.64 cm), due to handling weight, a block of the present invention may be 48 inches (122 cm) or more in length. and can maintain ease of handling due to its lower density. for example, 300 kg/cubic meter.

The lime component can act primarily as a binding agent, holding the other components together. However, any suitable binding agent may be substituted where, for example, a stronger binding agent is required. Suitable alternative binding agents may include polymer based agents, for example silica sand, pozzolans, polyester resins, Portland or similar cement or gypsum. Such alternative agents can also be used in combination with the lime component of the preferred embodiment.

The hemp fiber and tow component can provide insulating properties, bulk, support and strength to the batt and the structural members of the batt. However, any alternative material or combination of materials that can provide similar desirable properties may be used as an alternative. Some organic alternatives include fibrous materials, such as corn, cereal grain, straw, etc. Hemp tow is a preferred material, primarily due to its insulating qualities relative to the other fibers.

Alternatively, non-organic materials such as polystyrene/polystyrene foam or non-recyclable plastics can be used. Said materials can also be used in ground form. Structural fibers (oriented cellulose yarns, plastics, metallic or carbon filaments) can also be incorporated or replaced. The application of these non-organic alternatives can provide an additional advantage, since these non-recyclable materials can be captured from the environment or can add different qualities to the blocks (resistance, conductivity, electrical or RF shielding, noise reduction, etc.) .

Recyclable and sustainable

The composition of a preferred embodiment comprises hemp tow, flax, hydraulic lime and hydrated lime. The mainly fibrous-lime combination is organic and consists of biorecyclable material. When the useful life of a structure using such blocks comes to an end, its components can be recycled. For example, the entire block can be ground and remixed for other downstream applications.

The components of the composition are also sustainable. For example, hemp tow, in addition to its favorable properties, is readily available and grows very quickly with little water and fertilizer.

Other favorable properties can be realized by the fibrous lime composition of the preferred embodiment. In particular, such a combination allows the building to "breathe". Air and moisture can move in and out of the blocks at a very slow rate. The use of a vapor barrier may not be required.

The composition may also be resistant to mold, termites, and other insect pests.

A structure using the block composition of the preferred embodiment may allow fire resistance, due to the properties of the mixture of lime and hemp tow, or other compositions.

In another embodiment, the blocks of the present invention may be further coated with a lime finish. A block of the present invention may be covered with several layers of lime, for example five or more.

A structure using the blocks of the present invention can be bonded together to become monolithic. Such properties can be especially beneficial, particularly in areas prone to earthquakes, hurricanes, or tornadoes. Waterproofing or moisture resistance properties can also be realized, particularly by using the lime component. The lime component may also allow a block in the preferred embodiment to "heal" itself. For example, a crack in lime coating can close over time when subjected to moisture.

Carbon dioxide capture

The carbon dioxide scavenging properties of a block comprising the preferred composition of the present invention allows for the removal and scavenging of the greenhouse gas carbon dioxide from the Earth's atmosphere. The hemp tow component of the composition can capture carbon dioxide at a rate of more than about 20 tons per hectare as the plants grow.

The lime-hemp tow composition blocks of the preferred embodiment are estimated to have the ability to capture/absorb greater than about 100 kilograms of carbon dioxide per cubic meter. The lime component may use carbon dioxide to cure and set the mix. An average house comprising such blocks, for example, can capture about 13,000 kilograms of carbon dioxide during block production and can continue to absorb carbon dioxide for about 100 years. manufacturing methods

The manufacture of the blocks of the present invention can be achieved through the use of a mold process. During manufacturing, the embedded struts can be cut to the desired length, such as 20.32 cm (8 inches) long. A hole may be drilled through the bodies of those members which will serve as conduits for the tensioning means.

A desired number of struts and perforated tubes are placed in a mold at the desired positions, on a template. A mixture comprising the components of the block composition can be blended and blended. The mixture can then, for example, be poured, sprayed or injected into the mould.

The composition can be compressed and/or heated and allowed to solidify. During the curing process, carbon dioxide can be injected or passed (or through ducting into) the curing block, reducing curing time. Depending on the lime composition used, the blocks can also be autoclaved to control ambient temperature, humidity and carbon dioxide.

A lime coating can be applied to the interior and exterior face of the blocks at the time of manufacture, which can increase the strength of the block and reduce construction completion time.

The blocks of the present invention can be prefabricated and then cut as desired on the job. Building structure and related materials

The present invention also describes a structure and related construction materials, as illustrated in Figures 21-33.

In a preferred embodiment, said building materials may include blocks as disclosed in the present invention. Consequently, the blocks used in the structure of the present invention can be load-bearing, tensile-bearing, and insulating.

The blocks used may have standard building construction dimensions. Height, width, and length may vary, depending on the application, orientation, and desired insulation requirements. For example, the blocks used for the walls of a structure may have a standard thickness of 27.94 cm (11") and height of 20.32 cm (8"), while their length varies. Roof framing blocks can be 12" (30.48 cm) high and 16" (40.64 cm) wide.

Building materials may also be prefabricated before being transported to a planned construction site for assembly.

The structure of a house of 130 square meters (1400 square feet) is given as an example below, one square foot corresponds to 0.093 m2.

wall blocks

Wall blocks can be of a standard height and width, and can vary in length. Wall blocks can be a standard 11" deep and 8" high, and can vary in length. The total count below includes blocks that can be cut on site.

4": 8

8": 12

12"-2 stanchions: 13

12"-4 stanchions: 29

16": 7

20": 13

24": 63

32":97

36": 43

48": 644

Total wall block count: 929

48" wall starter strips (can be made from pressure treated plywood): 65

roof blocks

R = ceiling

Ed = edge (always 48")

S = boot

E = extreme

P = peak

Total counts include blocks that can be cut on site.

R24': 1

R32": 2

R48": 198

Network: 20

Re24:2

Re32:1

Re48:19

Red:2

RS24:1

RS48": 23

Red:2

Rp24": 2

Rp48": 21

Speed:2

Total roof block count: 296

beam blocks

Standard 16": 36

16" end block: 1

16" End Cap: 2

Standard 12": 4

12" End Cap: 1

Total Beam Block Count: 44

structural ties

Structural ties can be breathable and, in one embodiment, can be made of 16-gauge stainless steel mesh.

Structural wall/ceiling tie: 23

Peak mooring: 30

Square mesh tie: 25

Structural support: 5

Wood ( rough cut unless otherwise noted)

1 1/2"x12"x12" under 12 beam: 1

1 5/8"x12"x16" under 16" beam: 2

2'x6' Roof Starter Block Bracket (1 each):

37' - 8" long

35' - 8" long

11' - 8" long

2' long

2x6 Window/door headers and footers x6 (coated):

6' - 4" long: 2 (master bedroom window)

9' long: 2 (living room window)

5' long: 1 (front door)

8'- 4" long: 1 (back door/window)

3' - 8 ⁄" long: 1 (foot of rear window)

6' long: 4 (bedroom windows)

2x4 door/window trim x4 (coated)

6' - 8" long: 4 (doors)

3' - 4" long: 8 (windows - not living room)

4' - 8" long: 2 (living room windows)

bras

Fasteners used must be compatible with lime construction and may include stainless steel or ceramic-lined fasteners.

Structure finish

In one embodiment of the present invention, lime mortar or other suitable mortar may be brushed on all faces of the block that are adjacent to another face of the block. As a result, this can create a structure that is monolithic and sealed.

The interior walls of the structure of the present invention may be of lime plaster, which may be colored or have breathable paint applied to it. In an alternative embodiment, no additional application to the interior walls is required. In another embodiment, the interior walls may also be covered with drywall, wood veneer, or brick, preferably with a minimum air space of approximately 1" constructed between the bricks and the interior panels.

The exterior walls of the structure of the present invention may have a single layer of biofibers and a lime finish applied. Such an application can add monolithic quality and strength to the construction with a more finished appearance and a color finish that will not fade or fade. In another embodiment, the exterior walls may have a mortar application or "stucco look." Such an application can also add monolithic quality and strength to the construction with a more finished appearance and a color finish that will not fade or fade. In a further embodiment, typical wall cladding brick veneer and other non-permeable materials may be used, and a minimum gap of 1" (2.54 cm) from the block surface must be maintained. In yet another embodiment, no additional application is required on exterior walls, and blocks may be formed with a decorative exterior surface on them Blocks may have embossed or patterned surfaces for decorative or other purposes such as sound absorption, water shedding, the reflectivity of light, etc.

Any roofing material known in the art can be used in conjunction with the roof of the structure of the present invention. If non-breathable material is used, there should be a minimum gap of approximately one inch (2.54 cm) between the non-breathable material and the roof block. In one embodiment, the roof may be coated with, for example, a 100-year, 7-layer whitewash finish. In an alternative embodiment, the roof may further comprise breathable biofiber "clay-like" tiles which may not require an air gap.

Preferred Proposed Block Benefits

A more preferred embodiment of the present invention would have some or all of the following features:

• Strong load carrying capabilities

• Excellent insulating properties R26 to R40 or A = 0.07 W/m.K with 100% thermal bridge breakage

• Excellent fire rating

Classification of ecologically sustainable construction material, zero carbon or negative co2 Good thermal mass and thermal inertia characteristics to regulate the interior temperature Excellent permeability to air and humidity

It complies with existing building standards and dimensions, making it easy for contractors and architects to implement. Conventional fasteners such as stainless steel or ceramic coated screws can be used.

Lightweight for easy handling and no skilled labor required for construction assembly Very fast construction, constructed walls are weather resistant and finishes can be applied immediately. Factory prepared front surfaces require minimal interior and exterior finishing

Standard sizes can allow robotic or machine-assisted assembly on site

Integrated conduit routes within blocks to accommodate power and utilities

Claims (8)

1. A structural block assembly having a tensioning system to contribute to the tensile load bearing attributes of the structural assembly, the structural assembly comprising: a plurality of building blocks, each building block having a first surface, an opposing surface, opposing side surfaces, and opposing end surfaces; a plurality of load-bearing structural members embedded within each structural block, these being strut members, a protruding end of each embedded member extending from said first surface of the structural block, wherein one or more of the embedded strut members comprise a longitudinal cavity through them; a plurality of openings extending into the structural block from said opposite surface of the structural block, each opening adapted to engage a protruding end of an embeddable member of an adjacent structural block, the protruding end of each embeddable member extending from the first surface a distance equal to the depth of the opening within the block such that the protruding end of an embed member of one block engages an opening in an adjacent block and is in direct contact with the terminal embed end of an embed member of the block. adjacent block; Y wherein the embedded members of the assembled structural blocks form a stacked structure that forms a load-bearing structural member, wherein the assembly further comprises tensioning means placed within the longitudinal cavities of the embedded members, wherein the cavities of the members embedded in adjacent structural blocks are aligned to form a longitudinal duct to receive the tensioning means therein; wherein the openings and protruding ends of the embedded members function as locating means to accurately position a structural block relative to an adjacent block during assembly while also contributing to the load-bearing attributes of the block under compression; characterized in that each structural block further comprises a compression strut extending in an approximately perpendicular direction between and in contact with a pair of embedded members of the structural block. 2. The structural block assembly of claim 1, wherein the tensioning means comprises a cable, a non-stretching tension cable, or a rod. 3. The structural block assembly of claim 2, wherein the tensioning means further comprises a tensioning end assembly. 4. The structural block assembly of claim 3, wherein the tensioner end assembly is a hexagonal stamping tensioner. 5. The structural block assembly of claim 1, further comprising a strut cap positioned over the protruding end of one or more of the embedded members. 6. The structural block assembly of claim 1, wherein the structural blocks are made of a primarily fibrous material and a primarily lime-based material including hydraulic lime or hydrated lime. 7. The structural block assembly of claim 1, wherein the embed members are aligned within each block in parallel pairs, one embed member parallel and closer to one side of the block and the other embed member of the pair parallel and closer on the opposite side of the block. 8. Use of the structural block assembly of claim 1, in the manufacture of a floor, wall or ceiling of a structure, or in the manufacture of a structure.